8 Expert Tips on How to Avoid Pooping Midrace
Sometimes the only thing standing between you and a new PR is a midrace porta-potty break. Even if you manage to cross the finish line without needing a bathroom stop, symptoms such as stomach cramps, gas, and urgency may have been enough to knock you off your goal pace.
If you’re wondering what you can do to avoid needing the bathroom on the run, you’re not alone—even professional runners make emergency bathroom stops in big races.
To find out why these bathroom snafus happen and how to avoid them, we chatted with three experts who research or treat gastrointestinal (GI) issues. They shared eight strategies that will help you take on your next race with more comfort, confidence, and your mind and stomach at ease.
Track Your Intake
“We are all different in how we react to specific foods,” says Hardeep Singh, MD, a board-certified gastroenterologist based in Southern California. “The best thing to do is to track what foods you eat and how that correlates with your bowel movements in the weeks leading up to a race.”
This can help you identify foods that may cause you to run for the shrubs during those training runs. Common dietary triggers include lactose, sugar substitutes, wheat, gluten, soy, caffeine, and eggs, Singh says.
Patrick Wilson, PhD, RD, an endurance nutrition researcher and author of The Athlete’s Gut, adds that foods high in FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) can also increase the risk of GI symptoms. FODMAPs are short-chain carbohydrates that are poorly absorbed in the small intestine. They can draw extra water into the gut and are quickly fermented by gut bacteria, which may increase the risk of bloating, gas, or diarrhea during a run—especially in people who are sensitive to them.
Some high-FODMAP foods are familiar culprits of GI distress, such as beans, dairy, and sugar alcohols. But others may surprise you. Apples, watermelon, honey, mangoes, dried fruit, and wheat-based breads and cereals can be problematic for some runners—especially in large portions.
Moderate Fat and Fiber Consumption
One to two days before your race, be cognizant of your intake of both fat and fiber. This can help ensure you don’t have any more food than absolutely necessary hanging around in your GI tract when you cross the starting line, says John Pandolfino, MD, Northwestern Medicine’s chief of gastroenterology and hepatology.
Dietary fat and fiber slow digestion and require more energy to break down in the gut compared to simple carbohydrates. And, since bloodflow is diverted away from the gut and toward the muscles when you run, you don’t want to make digestion any more difficult than it needs to be.
You don’t need to—and shouldn’t—drastically overhaul your diet. But it can be helpful to pay attention to your intake of cream sauces, fried foods, and cruciferous vegetables such as broccoli and cauliflower if they often bring trouble, Pandolfino says.
One important note: During training, consuming fiber is beneficial to keep your bathroom habits regular. However, in large amounts—or when combined with prerace jitters and intense exercise—it can contribute to diarrhea.
Pay Attention to Performance Aids
Many runners have a love-hate relationship with caffeine. While the fatigue-fighting stimulant can definitely improve exercise performance (which is why many running gels contain it), it can also send your bowels into high gear, says Pandolfino.
FYI: A single pouch of GU Energy Gel contains up to 40 milligrams of caffeine. (That’s less than half of the average 8-ounce cup of coffee, which contains about 95 milligrams.) However, caffeine content varies from brand to brand and even from flavor to flavor—it can range from fewer than 20 milligrams to more than 100. And when consumed every 30 to 60 minutes throughout a race like a half or full marathon, even smaller doses can add up. You may have to experiment with different amounts of caffeine in the months of training leading up to your race to determine what you can tolerate.
Additionally, research shows that various compounds in coffee—not just caffeine—can increase the body’s levels of gastrin and cholecystokinin, two hormones that speed up how fast things move through the gut. For this reason, any coffee is usually best consumed at least an hour before start time, Pandolfino says. That way, you have a good chance of completely emptying your system with time to spare before you head to the starting line.
Another performance booster you may want to be wary of is sodium bicarbonate, or “bicarb” products. Taking bicarb has been shown to help buffer the buildup of lactate in muscles during intense exercise as a way to delay fatigue. (Maybe you’ve seen runners slurping down a clear, gelatinous goo with a spoon—that’s Maurten’s Bicarb System.) But it’s not always easy on the stomach. “Sodium bicarbonate is becoming increasingly popular, but it’s one of the riskiest in terms of gut side effects,” says Wilson.
Get Your Nerves in Check
Prerace butterflies are totally normal, and a little nervousness can be motivating and energizing as you prime yourself to compete. But excessive anxiety or overwhelming stress on race day doesn’t bring the same benefit. Research by Wilson and his colleagues found that endurance athletes with higher levels of anxiety were significantly more likely to report GI symptoms during races.
“The brain and gut are directly wired to each other, and any stressor can contribute to a change in bowel habits,” Singh adds. The best way to keep prerace jitters from going straight to your gut is to practice calming your nerves and staying mentally grounded. Everything from taking slow, deep breaths to laying out everything you need the night before race day can help eliminate excessive stress.
Schedule a Prerace Poop
“If you can get on a regular schedule, ideally you should try to time it so that you have a good, healthy bowel movement a few hours prior to race time,” Singh says. That way, you’ll have the least amount of food in your system during the race.
One of the best ways to set yourself up for a successful prerace poop is to give yourself enough time on race morning. That might mean planning additional minutes to sip a hot beverage or just enjoy a little peace and quiet in the bathroom. The less rushing, the better.
Slow Down Your Fueling
“In general, eating and drinking slowly during a race is helpful in preventing gastrointestinal distress,” Singh says. Sipping and nibbling slowly allows your gut to absorb nutrients with less work and more efficiency, which can minimize any stomach upset. Also, eating too fast and gulping generally involve swallowing some air, which can lead to gas, cramps, and bloating.
That said, it’s important to avoid under-fueling. If you reduce how much you eat or drink during every fueling session, make sure that you increase feeding frequency proportionally.
“Significantly under-fueling is also a possible cause [for GI issues], especially during longer events where hypoglycemia [low blood sugar] is more likely,” Wilson says. “In those cases, under-eating can lead to or exacerbate nausea.”
Manage Hydration—and Mind the Heat
According to Wilson, both dehydration and overhydration (hyponatremia) can trigger GI symptoms. “Dehydration probably leads to a larger range of symptoms, where hyponatremia from fluid overload is more specifically tied to nausea,” he says.
Dehydration becomes more of a concern when the temperature is high. Additionally, hot weather creates another physiological stressor because the body diverts blood away from the gastrointestinal tract and toward the skin to help dissipate heat. Less bloodflow to the gut can disrupt digestion and damage the intestinal lining, increasing the likelihood of nausea, cramping, and diarrhea.
What About Imodium?
Loperamide, better known as Imodium, is a common antidiarrheal medication that works by slowing gastrointestinal transit. For this reason, some runners use it to prevent needing to poop during a race.
However, Wilson doesn’t recommend it without consulting your doctor first. “If a runner feels like they need to use loperamide to manage symptoms, I’d suggest they work with a qualified practitioner to help uncover the underlying cause of their problems,” he says.
Wilson explains that not much research has been done on how loperamide affects GI function during intense exercise. So, while the drug is recognized as a fairly safe medication if used within recommended dosages, much remains unknown about its safety when combined with high-intensity or prolonged exercise like running. Wilson adds that taking loperamide when exercising in the heat can be even riskier.
And unfortunately, sometimes you can do everything right and you still need to go. If that happens, make a beeline for the nearest racecourse porta-potty and use Shalane Flanagan’s tip from her bathroom pit stop at the 2018 Boston Marathon: “Don’t take the shorts all the way off,” she said on the Ali on the Run podcast in 2020. “Just pull them to the side really quick.”
The results speak for themselves: Shalane made it in and out of the porta-potty in under 14 seconds.
Morgan is a gear editor who has been with Runner’s World since 2017. She started as an intern ghostwriting The Warmup, a bygone version of the daily RW newsletter. Now, she tests and reviews anything you might find on runners’ feet-from crew socks and compression boots to carbon-plated super shoes.
A lifelong runner and shoe geek, Morgan has been chasing the perfect pair of kicks since she joined her grade school cross-country team. Since then, she ran as a Division I walk-on for the cross-country and track & field teams at the University of Delaware, where she studied English and Biology. She has one full marathon under her belt, and has raced more halfs and 5Ks than she can count.
